Education Development Center, Inc. (EDC), in collaboration with Boston College, Harvard University, and the University of California, Berkeley will plan to deliver and evaluate interventions designed to enhance the literacy, mathematics, science, and self-regulation and social development of children from low-income families in preschool programs in three geographical regions. Our interventions consist of curricula that are delivered to entire preschool programs by program staff. Our research employs: Random assignment of clusters of preschool classrooms to condition; evaluation of classroom practices to determine the extent to which programs adopt and sustain practices implemented during the two curriculum interventions; Assessment of the long-term impact of the interventions using longitudinal analyses; assessment of the independent impact of the distinct components on children's language, literacy, mathematical, scientific reasoning, self-regulation and social skills using cross-sectional studies; Evaluation of the extent to which the impact of a social, emotional and self-regulatory component enhances gains that result from a curriculum component targeting mathematics and literacy; Examination of the impact of augmenting curriculum interventions with materials for home use. During the planning year, we will work with other N.l.H.-funded projects to help to create a strong consortium; Refine our research design and select and develop research tools to assess project impact; Refine our interventions; and Build relationships and develop research structures for use with our program partners.